package com.gph.saviorframework.uitl;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import java.security.SecureRandom;

/**
 * Created by ISCAS_YT on 2016/12/7.
 */
public class DesUtils {

    private static final String DEFAULT_PASSWORD_CRYPT_KEY = "_JSXS_";

    private static final String DES = "DES";
    private static Cipher cipher = null;

    static {
        // Cipher对象实际完成加密操作
        try {
            cipher = Cipher.getInstance(DES);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private DesUtils() {

    }

    public static byte[] encrypt(byte[] src, byte[] key) throws Exception {
        // DES算法要求有一个可信任的随机数源
        SecureRandom sr = new SecureRandom();

        // 从原始密匙数据创建DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);

        // 创建一个密匙工厂，然后用它把DESKeySpec转换成
        // 一个SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey securekey = keyFactory.generateSecret(dks);

        // 用密匙初始化Cipher对象
        cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);

        // 正式执行加密操作
        return cipher.doFinal(src);
    }

    public static byte[] decrypt(byte[] src, byte[] key) throws Exception {

        // DES算法要求有一个可信任的随机数源
        SecureRandom sr = new SecureRandom();

        // 从原始密匙数据创建一个DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);

        // 创建一个密匙工厂，然后用它把DESKeySpec对象转换成
        // 一个SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey securekey = keyFactory.generateSecret(dks);

        // 用密匙初始化Cipher对象
        cipher.init(Cipher.DECRYPT_MODE, securekey, sr);

        // 正式执行解密操作
        return cipher.doFinal(src);
    }

    public static String decrypt(String data) {
        try {
            return new String(decrypt(hex2byte(data.getBytes()),
                    DEFAULT_PASSWORD_CRYPT_KEY.getBytes()));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public static String decrypt(String data, String key) {
        try {
            return new String(
                    decrypt(hex2byte(data.getBytes()), key.getBytes()));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public static String encrypt(String data) {
        try {
            return byte2hex(encrypt(data.getBytes(),
                    DEFAULT_PASSWORD_CRYPT_KEY.getBytes()));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public static String encrypt(String data, String key) {
        try {
            return byte2hex(encrypt(data.getBytes(), key.getBytes()));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public static String byte2hex(byte[] b) {
        String hs = "";
        String stmp = "";

        for (int n = 0; n < b.length; n++) {
            stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));
            if (stmp.length() == 1) {
                hs = hs + "0" + stmp;
            } else {
                hs = hs + stmp;
            }
        }

        return hs.toUpperCase();
    }

    public static byte[] hex2byte(byte[] b) {
        if ((b.length % 2) != 0) {
            throw new IllegalArgumentException("长度不是偶数");
        }

        byte[] b2 = new byte[b.length / 2];
        for (int n = 0; n < b.length; n += 2) {
            String item = new String(b, n, 2);
            b2[n / 2] = (byte) Integer.parseInt(item, 16);
        }

        return b2;
    }

    public static void main(String[] args) {
        String url = "jiusanwenyuan123"; //jiusanxueshe
        url = DesUtils.encrypt(url, "jiusanxueshe");
        System.out.println(url);
        System.out.println("===================================================");
        System.out.println(url.length());
        url = DesUtils.decrypt("CFF4D0D9F43D0F51810CA9544F61383A", "jiusanxueshe");
        System.out.println(url);
        System.out.println(DesUtils.decrypt("A7BE3013ED683F9FF53E143A4DB31A111B350966A0E30143", "jiusanxueshe"));

        System.out.println("===============================================");
        System.out.println(DesUtils.decrypt("6A9034B974351E2DF73AE35E20CD3A37", "jiusanxueshe"));
        System.out.println(DesUtils.decrypt("D6B0721ED86332B5396476B348DF3EAD10A5C52699D4DFE1", "jiusanxueshe"));
        System.out.println(DesUtils.decrypt("CF38FEA46BEAF5896976EDBF708987D8", "jiusanxueshe"));
    }
}
